1. Field of the Invention
The present disclosure relates to a display device, and more particularly, to an alignment structure which is provided between a signal pad and a signal driver, for connecting the signal driver to the signal pad.
2. Discussion of the Related Art
Liquid crystal display (LCD) devices, plasma display panels (PDPs), organic light emitting display devices (OLED), etc. have been developed as flat panel display devices replacing cathode ray tubes (CRTs). In such flat panel display devices, a large-sized screen has been realized by reducing the weight and the volume of the display devices and a quality has been greatly enhanced from continuous research and development for better response time and image quality, etc.
Recently, in addition to research and development in technology, research and development in product design is being done to appeal to consumers. As an example of such research and development, a borderless display device has been proposed in which an upper case is removed, and thus, a separate case is not exposed to a display surface which displays an image. Therefore, the aesthetic appearance of the borderless display device is enhanced in design, and thus, the borderless display device satisfies the purchase requirements of consumers. However, various problems occur in the manufacturing process.
Hereinafter, a related art display device will be described with reference to the drawing.
FIG. 1 is a schematic plan view of a related art display device.
As seen in FIG. 1, the related art display device includes a substrate 10, a gate driver 20, and a data driver 30.
The substrate 10 includes a display area, which displays an image, and a non-display area which cannot display an image. The non-display area is formed outside the display area.
A plurality of pixels are formed in the display area. Each of the plurality of pixels includes a gate line, a data line, and a thin film transistor (TFT). Each pixel emits light of a certain wavelength.
The gate driver 20 is attached to a first side of the substrate 10, and for example, is attached to a left non-display area of the substrate 10. The gate driver 20 supplies a gate signal to the gate line. To this end, the gate driver 20 is electrically connected to a gate pad 26 which is provided in the left non-display area of the substrate 10, and the gate pad 26 is connected to the gate line through a gate link 25.
The gate driver 20 includes a flexible printed circuit film connected to the gate pad 26 and a gate driving integrated circuit (IC) 21 mounted on the flexible printed circuit film. The gate driving IC 21 generates the gate signal, and supplies the generated gate signal to the gate pad 26 through the flexible printed circuit film.
The data driver 30 is attached to a second side of the substrate 10, and for example, is attached to an upper non-display area of the substrate 10. The data driver 30 supplies a data signal to the data line. To this end, the data driver 30 is electrically connected to a data pad 36 which is provided in the upper non-display area of the substrate 10, and the data pad 36 is connected to the data line through a data link 35.
The data driver 30 includes a flexible printed circuit film connected to the data pad 36 and a data driving IC 31 mounted on the flexible printed circuit film. The data driving IC 31 generates the data signal, and supplies the generated data signal to the data pad 36 through the flexible printed circuit film.
A process of aligning the gate pad 26 and the gate driver 20 is performed for connecting the gate driver 20 to the gate pad 26. Also, a process of aligning the data pad 36 and the data driver 30 is performed for connecting the data driver 30 to the data pad 36.
In an enlarged view of FIG. 1, for convenience, only an element for aligning the data pad 36 and the data driver 30 is illustrated.
As seen in the enlarged view of FIG. 1, an alignment process of aligning the data pad 36 and the data driver 30 is performed by using a first alignment mark 40 and a second alignment mark 50.
The first alignment mark 40 is formed at the data driver 30, and in more detail, is formed on the flexible printed circuit film of the data driver 30.
The second alignment mark 50 is formed on the substrate 10, and in more detail, is formed in the upper non-display area of the substrate 10.
The first alignment mark 40 includes an accommodating groove for accommodating the second alignment mark 50. The second alignment mark 50 is formed in a tetragonal structure such that it can be accommodated in the accommodating groove.
Therefore, the alignment process is performed in order for the second alignment mark 50 formed on the substrate 10 to be accommodated in the accommodating groove of the first alignment mark 40 formed on the data driver 30. In this state, the data driver 30 is connected to the data pad 36.
FIGS. 2A and 2B are process views illustrating a process of aligning the data driver with the data pad in the related art display device, and relate to the above-described display device of FIG. 1. Therefore, like reference numerals refer to like elements throughout.
First, as seen in FIG. 2A, a position of the data driver 30 is adjusted while moving the data driver 30 to an upper side of the substrate 10, so that the second alignment mark 50 formed on the substrate 10 is accommodated in the accommodating groove of the first alignment mark 40 formed on the data driver 30.
Subsequently, as seen in FIG. 2B, the alignment process of aligning the data driver 30 and the data pad 36 formed on the substrate 10 is finished by lowering the data driver 30 in a state where the second alignment mark 50 is accommodated in the accommodating groove of the first alignment mark 40.
As described above, in the related art, the alignment process of aligning the data driver 30 and the data pad 36 is performed by using the first alignment mark 40 which is formed on the data driver 30 and includes the accommodating groove, and the second alignment mark 50 which is formed on the substrate 10 and is accommodated in the accommodating groove. In this case, there is a problem in which the first alignment mark 40 is recognized at a display surface of the display device.
In particular, in the related art, since the first alignment mark 40 formed in the data driver 30 should include the accommodating groove, there is a limitation in decreasing a size of the first alignment mark 40. The size of the first alignment mark 40 is very large at the display surface and causes reduced visibility. For this reason, it is difficult to apply the first alignment mark 40 to a borderless display device in which aesthetics is very important.